Israel on Thursday expressed concern that the UN peacekeeping force in the Golan Heights could pull out altogether after Syrian rebels snatched 21 of their troops in the ceasefire zone bordering Israel.
The soldiers, Filipino members of the UNDOF peacekeeping force, were taken hostage on Wednesday by gunmen who said they would be held until troops loyal to Syrian President Bashar al-Assad pulled back from Jamla village in the southern province of Daraa.
The rebels also accused the UN force of favouring Israel.
"This kidnapping is likely to convince countries who participate in this force to bring their troops home, which would undoubtedly create a dangerous vacuum in no man's land on the Golan," an Israeli official told AFP, speaking on condition of anonymity.
"Since its creation, this force has fulfilled its mission which was to keep the peace," he said.
Since 1974, the UN's Disengagement Observer Force (UNDOF) has been monitoring the Syrian side of the armistice line with a force of 1,200 troops, although its number has recently dropped to 1,000.
Israel fears that the departure of UNDOF troops could leave a vacuum in the ceasefire zone between Syria and the Israeli-occupied sector of the Golan Heights, leaving it open to infiltration by hardline militant groups.
The top-selling Yediot Aharonot daily said Israeli officials were concerned that the UN force in the area would "be dismantled and that al-Qaeda members will take control of the buffer zone between Israel and Syria."
"There is concern that al-Qaeda will take over this buffer zone and the villages near Israel," the paper said of the 80-kilometre (50-mile) strip of land which is between half a kilometre and 10 kilometres wide (500 yards to six miles).
Syria remains formally at war with Israel, which captured part of the Golan during the 1967 Six Day War and annexed it in 1981, a move not recognised by the international community.
Israel controls some 1,200 square kilometres of the strategic plateau, while around 510 square kilometres remain in Syrian hands.
The UN has reported a growing number of incidents in the Golan over the past year with its forces in the buffer zone coming under fire from the Syrian side, prompting moves to boost security for the mission.
By the end of February, there were about 1,000 troops from Austria, Croatia, India and the Philippines participating in the UNDOF force.
Last week, Croatia said it was withdrawing its 100 troops over fears for their safety, following similar moves by Japan in recent months. Canada pulled its troops out in March 2006.